The present invention relates to a flexible sealed radioactive film useful for medical treatments and a method for producing such radioactive films.
Radioactive materials have been used in the medical treatment of diseased tissues. Such radioactive materials may be implanted into a patient at the site of the diseased tissue. It is desirable to have the radioactive material in a form which will permit it to be used to irradiate the diseased tissue while minimizing damage to nearby healthy tissue. Therefore, it is desirable to have a source which will uniformly irradiate an area being treated with a controlled desired dosage of radiation. Also desirable is a method of easily applying such sources to the area being treated.
Radioactive iodine sources have been used in radiation therapy in the form of a radioactive seed which is implanted into the patient at the site being treated. Such methods of radiation treatment provide radiation patterns in a circumferential area around the whole seed. Although such seeds provide adequate treatment for some diseased tissues, they are unable to provide adequate radiation for areas of the body which require more specific or irregular radiation patterns, such as the treatment of diseased eye tissue. Further, such seeds are difficult to place and retain in the desired area for treatment of residual tumor cells remaining on the walls of cavities resulting from surgical removal of a tumor from the body. Such residual tumor cells cannot be adequately treated by radioactive seeds.
Another method of treating diseased tissue is disclosed in Lemelson U.S. Pat. No. 4,674,480 in which fluid disposed within a container or capsule implanted in the diseased tissue is released to infiltrate the surrounding tissue. The fluid is rendered explosively radioactive when targeted within a living body by external radiation passed through the body to the container or capsule containing the radioactive fluid. This method has the disadvantage in that the fluid may infiltrate healthy tissue and other areas where radiation is not desired.
It is desirable to provide sources of radiation which can be readily adapted for application to the site of therapy and from which the amount of radiation to the site can be readily controlled. However, it will be appreciated that the prior art fails to disclose a truly convenient, advantageous and safe method for providing radioactive materials which provide maximum irradiation at an area of treatment while being easily applied to the treatment site. Also, the prior art fails to disclose a method for easily manufacturing large numbers of such radioactive sources.